This work is to gain basic knowledge concerning the behavioral, metabolic, and neuroanatomical bases of food-intake control and body- weight regulation. The working model is that the medial hypothalamus contains a mechanism which mediates both excitatory and inhibitory control of feeding in response to body nutrient depletion and repletion, respectively; and it is hypothesized that this function is a direct consequence of local metabolism of nutrients within the medial hypothalamus. Feeding patterns, hypothalamic respiration, and hypothalamic nutrient distributions are being studied under a variety of metabolic states.